The multi-homed mobile devices in the mobile cloud computing (MCC) systems can improve their throughput by allocating the application data over several paths simultaneously, enabled by the promising ...Multipath TCP (MPTCP) technology. Meanwhile, network attacks against current Internet infrastructures are likely to increase, especially with the widely deployment of MCC systems. When a MPTCP connection is under network attacks and becomes a poor-performing path or a broken path, it can significantly affect other stable paths and in the absence of related schemes to handle this, MPTCP will undoubtedly suffer from serious performance degradation. Moreover, applying MPTCP to cloud data delivery may generally lead to higher energy consumption and is not favorable to a power-constrained mobile device. In this paper, we propose MPTCP-La/E 2 , a low-rate distributed denial-of-service (LDDoS) attack-aware energy-efficient MPTCP solution aiming at: 1) avoiding the LDDoS-caused performance degradation of cloud multipath transmission, which has been seldom considered in existing MPTCP solutions and 2) optimizing the energy usage while still maintaining user's perceived quality of cloud multipathing services. The simulation results show that MPTCP-La/E 2 outperforms the baseline MPTCP in terms of QoS and energy-savings in a multihomed MCC network environment.
Mobile phones equipped with multiple wireless interfaces can increase their goodput performance by making use of concurrent transmissions over multiple paths, enabled by the Multipath TCP （MPTCP）. ...However, utilizing MPTCP for data delivery may generally result in higher energy consumption, while the battery power of a mobile phone is limited. Thus, how to optimize the energy usage becomes very crucial and urgent. In this paper, we propose MPTCP-QE, a nov- el quality of experience （QoE）-driven energy-aware multipath content delivery approach for MPTCP-based mobile phones. The main idea of MPTCP-QE is described as follows： it first provides an application rate-aware energy-efficient subflow management strategy to tradeoff throughput performance and energy consumption for mobile phones; then uses an available bandwidth-aware congestion window fast recovery strategy to make a sender avoid unnecessary stow-start and utilize wireless resource quickly; and further introduces a novel receiver-driven energy-efficient SACK strategy to help a receiver possible to detect SACK loss timely and trigger loss recovery in a more energy-efficient way. The simulation results show that with the MPTCP-QE, the energy usage is enhanced while the performance level is maintained compared to existing MPTCP solutions.
With the advancement of multimedia technologies and driven by the ever-increasing user interests in the variety of multimedia applications, the content-rich multimedia streaming services tend to be ...the most attractive service in future Internet. The multipath TCP (MPTCP), which uses multiple paths for parallel transmission and bandwidth aggregation, is considered to be the most potential transfer mechanism to satisfy the specific requirements of multimedia transmission in a multi-homed wireless network environment. However, the fully-reliable transmission nature of MPTCP can cause an unnecessary retransmission of expired multimedia data, block message from handing over to upper layer, and thus degrade the user-perceived multimedia service quality. In this paper, we propose a receiver-centric partial-reliable multipath transport solution (referred to as rec PR-MPTCP) to support real-time Internet multimedia applications. In the rec PR-MPTCP, a partial reliability extension is presented which runs at receiver side in order to offer a partial reliability multipathing service for multimedia applications. In addition, a new one-way delay-based bandwidth aggregation method is included into the rec PR-MPTCP in order to reduce the receive buffer blocking problem in MPTCP and increase multimedia services performance. Simulation results show that rec PR-MPTCP outperforms the current MPTCP solutions in terms of throughput performance and user-perceived quality of service.
With the diversified wireless network access technology and large-scale equipment of multinetwork interface devices expanding, network transmission performance for multi-homed terminals has been ...widely concerned by academic circles. More and more scholars have paid attention to Multipath Transmission Control Protocol (MPTCP) as one of the representative methods for studying path transmission performance. However, their studies ignore the impact of dynamic network environments on data transmission performance and seldom consider the priority of data transmission. Undoubtedly, not prioritizing packets will have a dramatic effect on the users experience in the heterogeneous networks. In this paper, we propose a novel priority-aware streaming media multipath data scheduler mechanism (PO-MPTCP) to achieve the following goals: (1) detecting the priority of all streaming media data; (2) achieving multiattribute-aware path evaluation and switching mechanism; (3) introducing a path-quality priority-driven data distribution mechanism to improve streaming multipath transmission performance. The simulation experiment shows that PO-MPTCP proposed by this paper improves the transmission performance of streaming media and reduces the transmission delay. For the result of simulation experiment, it is easy for us to find that PO-MPTCP is more efficient in data delivery than the standard MPTCP mechanism.
Applying Multipath TCP (MPTCP) towards transport-layer parallel multipath transmission to increase the throughput performance of mobile devices has attracted considerable attention. Significant ...results in this area have resulted in many highly promising solutions; however most of the existing solutions follow the conventional sender-centric design and the strict layering principle, without considering the fact that the receiver's intelligence and cross-layer activities can result in distinct performance advantages. In this paper, we propose MPTCP-RC, a receiver-centric cross-layer solution to aid MPTCP towards efficient parallel multipath data transmission in a wireless environment. In MPTCP-RC, the receiver performs path usage decision and cross-layer activity, by making use of its acquired first-hand knowledge of both transport layer and MAC layer, rather than only giving feedback to the sender then waiting for the decision. We evaluate and demonstrate the benefits of our proposal by simulations.
With the standardisation of the fifth generation (5G) wireless network interface was established in 3GPP, the features of 5G arouse great interest both in academics and industry, even government. The ...significant advancements of 5G wireless network technology will make a great increase in the demand for content-rich streaming media services. What's more, many mobile devices with heterogeneous network interfaces (4G, WiFi, and even 5G) connect multiple paths for data delivery simultaneously. Multiple Transmission Control Protocol (MPTCP) is recommended by Internet Engineering Task Force (IETF) to multi-path parallel transmission, which is an important transport layer protocol. Although there are many attractive benefits by using MPTCP for data delivery, it becomes sensitive for MPTCP to network attacks. When a subflow with the MPTCP association suffers from some network attacks (e.g. denial of service attacks), there is undoubted that it will cause large numbers of retransmission data. Unfortunately, the regular MPTCP retransmission mechanisms retransmit data over the same path, which may cause receiver buffer blocking. In this study, the authors propose effective retransmission mechanisms in MPTCP for retransmitting data on a non-congested path. The simulation results show that the proposed retransmission mechanism has better performance than the regular’ in the network attacks.
•A method of detecting the air gap by using thin firm interference methods has been developed which is helpful to realize automation.•The law of ultrafast laser transmission and absorption in ...micro-region are discussed from a new angle, which is helpful to the simulation of temperature field and stress field.•Laser welding with good performance can be achieved at 2 μm thickness of air gap. and the glass welding with best tensile fracture strength is over 30 MPa.
In order to study the influence of air gap and focus position on the quality of ps-laser glass-to-glass welding we implemented a method of detecting the air gap between glass surfaces based on optical thin film interference. The method allows real-time optimization of the welding process. We measure the air gap between glass surfaces to be bonded and the laser focal position, which are set as the constraint conditions affecting the nonlinear self-focusing of the laser beam. The processing parameters of picosecond laser welding are determined and the welding strength and the morphology of bonded zone are detected and observed. Laser welding with good performance can be achieved with an air gap of 2 μm. SEM microscopy shows that the bonding region between two glass surfaces is very smooth in the vicinity of the tear-drop shaped cross-sectional structure of the welded glass. A tensile strength inspection fixture is designed, and we measured a tensile fracture strength of over 30 MPa for the welded glass. Through confocal microscope analysis, the width and depth of fracture morphology of welded samples are shown to change with air gap, which is consistent with the theoretical analysis.
The importance measurement of nodes in directed weighted networks is of great significance for theoretical research and practical application of networks. Aiming at the directed weighted network ...model in actual networks, based on the special transformation of graphs and tree roots, this paper proposes a comprehensive quantitative assessment method for the importance index of nodes based on the directed weighted network's global properties, local attributes, network location and bidirectionally propagation. This method transforms the nodes to be analyzed in the graph to root, constructs a bidirectional depth-affected XD tree and a breadth-affected XB tree with the node to be evaluated as the root of the tree. Then comprehensively consider the two-way influence of the node level, node neighbors and the closeness between neighbors in the two trees constructed, and the in-out effects, build a deep impact evaluation model at the two-way level, two-way neighbor information and comprehensive evaluation index of clustering coefficient. By calculating the comprehensive importance value of each node in the network, the comprehensive ranking of the importance of the nodes in the network can finally be obtained. The robustness experiment of ARPA network shows that the G value of the important node quantified by this method has absolute advantages, this method can effectively analyze key nodes in the network.
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